The Serpent
by Angie Astravic
Summary: Strange Transfiguration accidents befall Harry and Professor McGonagall; Hermione suspects a potion invented by Voldemort is responsible. Then Professor Snape's rare, valuable and highly embarrassing Famous Wizard card of Harry is stolen ...
1. The Serpent of Draco Malfoy

  
Author's Note: This story is the follow-up to "Under the Rose Bush" and "An Unwelcome Visitor". To avoid spoilers and pick up small details, you should read them first, although you can probably follow this one even if you don't. Those stories were written before _Goblet of Fire_ was published and are now alternate histories, but this one, which takes place during Harry's fourth year, merges back into the _Goblet of Fire_ timeline. 

* * *

  
  


— CHAPTER ONE — 

_The Serpent of Draco Malfoy_

  
'What could've happened to Professor McGonagall?' said Hermione anxiously. 'She's never been this late before.' 

The fourth-year Gryffindors had been sitting in the Transfiguration corridor for nearly half an hour that late September morning, waiting for Professor McGonagall to let them into the classroom. 

'First time for everything,' Ron shrugged. 

'Well, if she doesn't get here soon, there won't be much time left for the lesson,' muttered Hermione, checking her watch. 

'One missed lesson won't kill you, Hermione,' Ron said in exasperation. 'We've _had_ classes cancelled before.' 

'Yes, _cancelled_, but never a teacher just not shown up!' said Hermione, now sounding quite upset. 'Something might really be wrong!' 

'You worry too much,' Ron told her. 'Professor McGonagall probably got called off right as the bell rang. Something urgent came up and she didn't have time to come and tell us ...' 

'But surely she would've sent someone,' said Hermione. 

'Not if everyone was already in class,' Ron came back swiftly. 

Harry sat slumped against the wall, only half-listening to their wrangling. He had problems of his own to brood on. Snape had been casting dark looks at him all through breakfast that morning and he hadn't the faintest idea why. This was especially troubling in light of what had happened between the two of them over the summer holidays. Although Snape had loathed Harry from the moment Harry started at Hogwarts, Snape now had more reason to hate him than ever before ... and Harry had reason to believe Snape was going mad. 

Harry's gloomy reflections were cut short when Hermione, in a steely voice very much reminiscent of the absent McGonagall, said, 'We've sat here long enough! Harry, go and see if anyone in the staff room knows something. Ron, you check her office. I'll go to the hospital wing and ask Madam Pomfrey if she's ill.' 

The look on Hermione's face made it clear she would brook no argument. Harry reluctantly heaved himself up from the floor and trudged off to the staff room. When he rapped on the door, a sharp voice from within called out, 'Enter!' 

Harry's heart sank; it was Professor Snape. Before he could decide whether he should risk going in or not, the door was yanked open. Snape stood in the threshold, glaring down his hooked nose at Harry. 

'What are you doing here?' demanded Snape. 'Why aren't you in class?' 

'I was looking for Professor McGonagall,' said Harry. 'She never showed up for Transfiguration.' 

'Return to your classroom,' Snape snapped. 'And that will be twenty points from Gryffindor. For being in places you shouldn't be,' he added, giving Harry a meaningful look. 

Then, instead of going back into the staff room, Snape swept past Harry and went striding down the corridor. Harry stared after him in bewilderment. Twenty points from Gryffindor for going to look for a missing teacher was unusually harsh, even for Snape. And where was he going to in such a hurry? There was nothing in that direction except some unused classrooms, the staircase to the Ravenclaw common room ... _and a secret passage to the Owlery_. 

Harry felt as though he'd been hit in the stomach with a powerful Freezing Charm. He'd been dreading that Snape would try and do something horrible to Hedwig ever since his fourteenth birthday, when Snape had got his hand badly mauled trying to take a letter away from her. Next second, Harry was hurtling off in the opposite direction. The secret passage to the Owlery wasn't that much shorter than the regular route; if he ran flat out, he might be able to get there before Snape. 

When Harry arrived at the Owlery -- gasping for breath, his heart pounding -- all was calm. The owls were mostly asleep and neither Snape nor any other person was present. Harry collapsed against the doorway in relief. Still, he thought, as he leant there catching his breath, what with the funny way Snape had been behaving, it would be best to get Hedwig away from Hogwarts for a while. Snape could easily turn up at the Owlery later, and Harry couldn't stay there all day to guard her. 

Taking quill, parchment and ink from his bag, Harry scribbled a brief note to Mrs Weasley asking if Hedwig could stay at The Burrow for a couple of days, as she'd had a quarrel with another owl. This was rather unfair on Hedwig, who got on quite well with her fellow birds, but Harry didn't think Mrs Weasley would take him seriously if he'd tried to explain the situation with Snape. Harry poked Hedwig into disgruntled wakefulness and sent her soaring off, then went to rejoin Ron and Hermione. 

* 

Professor Snape walked swiftly along the Ravenclaw corridor, barely able to suppress a smirk. Not only had he managed to give Potter his comeuppance for last night's bit of attempted larceny, but it appeared that McGonagall had overslept for the first time in all his years at Hogwarts, and he intended to be the one to wake her up. Coming to a halt in front of a statue of Philippa the Slothful, Snape barked out, 'Patronus!' It slid aside to reveal the passageway to the staff quarters. 

Snape stepped inside and the statue moved back into place behind him. When he reached the door to McGonagall's rooms, he hammered on it loudly. There was no response. After waiting nearly a minute, Snape banged on the door again, shouting, 'McGonagall! Are you there?' Still no one answered. He seized the doorknob, meaning to give it a good rattling, but to his great surprise it turned easily and the door opened. 

In an instant, Snape had flattened himself against the wall just outside the door-frame and drawn his wand. However heavy a sleeper McGonagall might be, she wasn't stupid enough to leave her door unlocked -- not with the sort of things that had been going on at the school during the past three years. 

Snape stretched his arm out and tapped the door with his wand, causing it to fly violently open and hit the wall inside the room with a crash. It didn't sound as though there was anyone standing behind it, nor did any retaliatory curses come blasting out. 

Snape cautiously leant over to peer through the doorway. McGonagall's sitting room looked much as it had the one time he'd previously seen it -- walls lined with shelves full of old, tattered books, overstuffed armchairs gathered round a low table near the fireplace and an odd collection of objects on the sideboard. He supposed these must be the results of past Transfiguration experiments, as they certainly had no ornamental value. There was no sign of anything amiss, no sign of a struggle ... and no sign of McGonagall. 

'McGonagall?' Snape called, with the same lack of results as before. 

His eyes fell on a door at the far side of the room. Wand at the ready, he edged over to it and went through the same procedure in opening it as he had done with the first one. This door led to a bedroom. Curled up on the unmade bed was a tabby cat with square, spectacle-shaped markings around its eyes, looking up at him with an expression of mild startlement. 

Snape surveyed the cat, eyes narrowed. It _looked_ like the transformed McGonagall ... but why hadn't she answered him? Even if she'd somehow not heard all the racket he was making, she certainly knew he was here now. He would have expected rather more of a reaction than this. Particularly, Snape thought with a twisted smile, if she'd had to transform herself quickly because she wasn't dressed. 

'McGonagall?' he said. Another possibility suddenly occurred to him. 'Are you not able to transform back?' 

The cat completely ignored him. It lowered its head, eyes half-shut, and kneaded the bedspread with its paws. 

'Can you understand me?' said Snape. 'Meow twice if you can.' 

The cat closed its eyes and rested its chin on the bed, settling back to sleep. Snape gazed down at the creature, not at all happily. Apart from their abnormal reactions to certain potions, he knew very little about Animagi, but for one of them to no longer understand English could not be a good sign. Best Dumbledore have a look at her as soon as possible. 

Snape started towards the bed then stopped, realising that he had no idea how to handle an animal he wasn't planning to kill and pickle for future use as potion ingredients. He'd seen Filch pick up Mrs Norris, of course, but he'd also seen the blood splattered along the Defence Against the Dark Arts corridor two years ago, when a pair of exceptionally dim Slytherin second-years had tried to duplicate this feat. 

It had been some time since Snape had taken Care of Magical Creatures as a student and the subject had never much interested him anyway. As a teacher, at the staff table, he had heard Professor Kettleburn hold forth at great length on the importance of not showing fear, waving the stump of his left arm and pounding his wooden leg on the floor for emphasis. Hagrid's methods were evidently more effective, but appeared to consist mainly of being much too large for most magical creatures to damage. This was not a skill that could be readily passed on to others, as proved by the unfortunate incident of Draco Malfoy's arm. 

Draco ... he'd had cause for complaint against Hagrid on yet another occasion, Snape recalled ... something about a biting set book. In his mind's ear Snape could hear young Malfoy grumbling, '"Yeh've got ter stroke 'em," _honestly_.' But it seemed to have worked, as none of the _books_ had ended up in front of the Committee for the Disposal of Dangerous Creatures. 

So ... show no fear, and stroke them. Snape squared his shoulders and summoned up every ounce of authority that he'd developed in thirteen years as a master of Hogwarts. A trifle stiffly, he placed his hand on the cat's head and ran his fingers down its back. 'Good girl!' he said tersely, more as a command than an endearment. 'Nice puss!' 

After several seconds, the cat began to purr. Snape was not much comforted by this. It probably meant he could carry her without having his arms ripped to shreds, but had McGonagall been in anything approaching her right mind, Snape suspected his arms would already have been shredded for taking such liberties. He scooped her up and made for Dumbledore's office, moving as quickly as his dignity -- and the cat's temper -- would permit. 

* 

When Harry finally got back to the Transfiguration classroom, Ron and Hermione were waiting for him. 

'Did you find her?' said Hermione. 

'No, and Snape took twenty points off me for going to look,' said Harry. 'I tell you, he's --' 

'He's _coming_,' hissed Hermione, craning over Harry's shoulder. 

Harry dodged behind Ron and made himself small. He needn't have bothered, though; Snape swished past them at top speed, looking neither left nor right. 

'Well, something's definitely up with him,' Ron said, once Snape had passed out of earshot. 'Did you see? He had a cat!' 

Hermione was staring after Snape, open-mouthed. 

'Ron, that was _Professor McGonagall_ he was carrying down the hall!' 

Ron and Harry boggled. 

'You're _mad_,' said Ron. 'It was a _cat_ -- oh.' 

'D'you think he -- did something to her?' said Harry. 'Should we tell Dumbledore?' 

At that moment the bell rang for the next class. 

'I'll tell Professor Vector,' Hermione decided. She said rather nastily, 'Don't bother telling Professor Trelawney, I'm sure with her All-Seeing Inner Eye she already knows all about it.' 

Hermione headed off to the Arithmancy classroom, and Harry and Ron to Professor Trelawney's tower. 

When they met again for lunch in the Great Hall, Hermione said in a low voice, 'Professor Vector spoke with Dumbledore. She said he was taking care of things and to try and keep it quiet.' 

Professor McGonagall wasn't at the staff table. Snape was, looking even angrier than he had done at breakfast, but it was Fred and George Weasley at whom he was now glowering. Towards the middle of the meal, Dumbledore stood up and announced that afternoon Transfiguration classes were cancelled, as Professor McGonagall wasn't feeling well. 

After lunch was double Potions with the Slytherins, which had become a greater trial than ever to Harry this year. Snape had somehow got his hands on a Chocolate Frogs Famous Witches and Wizards card of Harry as a baby wearing a lacy white christening robe. Even more embarrassing than the robe was the letter from the manufacturer that had apparently come with the card. 

First Potions lesson of the year, Snape had read this letter out loud in his most sarcastic tones to the whole class. Its flowery descriptions of the baby Harry made Aunt Petunia's cooing over Dudley sound dignified and restrained. Harry had felt like sliding under the table and staying there until the end of term. The card was now prominently Spellotaped to the blackboard, so it wouldn't slip Draco Malfoy's mind to make snide remarks about it every lesson. 

Most unusually, Snape wasn't in the classroom yet when the bell rang. 

'I do hope nothing's happened to _him_,' said Hermione. 

'Why on earth not?' said Ron, staring at her as though she'd lost her mind. 

'I mean, after Transfiguration -- missing two lessons in one day --' 

Malfoy, who was sitting at the table in front of them, twisted around and gave her a contemptuous look. 

'Couldn't stand to go that long without showing off, could you, Granger?' he sneered. 

'You shut up, Malfoy!' said Ron furiously. 

'Ignore him,' Harry told Hermione, not particularly quietly. 'He's just jealous because you came out ahead of him in the Transfiguration exam last year -- and in all the other exams, all the other years, too.' 

Malfoy had a very ugly look indeed on his pointed face. 

'Hey, Granger!' he said. 'I'll give you a Transfiguration lesson!' 

Malfoy waved his wand in a complicated pattern and pointed it at Harry. A cloud of yellow sparks came shooting out, momentarily blinding him. This, however, was the least of Harry's difficulties. It felt as though a blanket had wound itself about his entire body, pinning his arms to his sides. His legs refused to hold him up and he fell forward, though fortunately not nearly as heavily as he would have expected. 

When Harry's vision cleared, he was lying on the floor surrounded by the feet of stools, tables and his fellow students, all of which had grown to an enormous size. Strong odours filled the room -- dust, stone, wood, leather and a peculiar combination of soap and people who hadn't bathed in a good while. Harry flicked out his tongue to get a better whiff. It seemed to extend much further than usual -- and why would sticking his tongue out help him to smell? 

Hermione screamed, and Ron bellowed, 'Malfoy!' 

There was a great shuffling of feet -- Harry could feel the vibrations in his very bones. 

Then Snape's voice roared, 'Weasley!' 

Harry felt a lesser shuffling and heard the sound of cloth uncrumpling. 

'He turned Harry into a snake!' Hermione shrieked. 

* * *

_ Disclaimer: All characters and concepts from the Harry Potter series copyright J K Rowling. _


	2. The Serpent of Professor Snape

  
  


— CHAPTER TWO — 

_The Serpent of Professor Snape_

  
'No I didn't, sir, she did,' said Malfoy at once. 'She said she'd missed her Transfiguration lesson and needed to practise.' 

Hermione spluttered in wordless indignation. 

'Silence!' snarled Snape. 'Stand away from him, all of you!' 

The feet -- the human ones, that is -- moved away from Harry. Snape barked out some unfamiliar words and Harry felt as though the blanket he was wrapped in was starting to unwind. Somehow, he pulled it tight to his body. After the events of that morning, he was in no mood to cooperate with anything Snape was trying to do to him. Snape performed the spell twice more and both times Harry stopped it working. 

Snape took several deep breaths, then said, 'Mr Malfoy, go and fetch Professor Dumbledore. He should be in --' 

Dumbledore! With a tremendous effort, Harry wriggled free of whatever it was that held him bound. The room returned to its normal size and Snape broke off in mid-sentence. Harry stood up, doing his best to seem innocently confused. 

'What happened?' he said. 'What was I doing on the floor?' 

This turned out to be a complete waste of his acting skills. After sending the rest of the class off to the library to write essays on Sweating Solutions, Snape marched Harry to the hospital wing, leading him through a door at the end of the ward up a corridor Harry had never been in before. 

Through an open doorway off it, Harry could see Dumbledore in an armchair reading a large and dusty book. Professor McGonagall was sitting up in a bed with an even larger and dustier book propped against her legs. She wasn't reading it at the moment, as her head was turned to allow Madam Pomfrey to peer into her ear with a tiny brass telescope. Dumbledore glanced inquiringly up at Harry and Snape as they stepped inside. 

'There's been another incident,' said Snape abruptly. Madam Pomfrey and Professor McGonagall stopped what they were doing to listen to him. 'I arrived at my afternoon Potions class to find that Miss Granger had turned Mr Potter into a serpent.' 

Harry wasn't letting this go unchallenged. 'Hermione? The last thing I remember was Malfoy pointing his wand at me.' 

Professor McGonagall gave Snape a sharp look. 

'Potter and his friends are constantly disrupting my lessons -- naturally they would try to shift the blame to someone else,' said Snape venomously. 'The point is, I was not able to reverse the Transfiguration. After performing the reversal spell three times without success, I was about to send for the Headmaster. At that instant, the Transfiguration reversed itself. Mr Potter claims to have no memory of anything that occurred whilst he was Transfigured.' 

Professor McGonagall began flicking rapidly through the pages of her book. Dumbledore gazed at Harry, a grave expression on his face. 

'I think, before anything else, Harry should be checked for after-effects,' he said. 'Poppy, if you would be so good ...' 

Madam Pomfrey took Harry to the dormitory for a thorough examination. After apparently finding nothing much wrong with him, she brought him back to Professor McGonagall, who questioned him intensively while Dumbledore looked keenly on. Harry was by now deeply regretting his impulse to resist Snape's efforts to untransfigure him, but didn't dare admit the real reason why the spells had failed. He told Professor McGonagall that all he remembered was a lot of smells and noise, and then finding himself lying on the floor. 

'But honestly, I feel fine,' he said. 'Malfoy probably just mucked up the Transfiguration somehow.' 

'There seems to have been no lasting damage done,' Professor McGonagall finally said. 'And some amount of confusion is only to be expected in a non-Animagus. This was the first time you've been Transfigured, Potter?' 

Harry nodded. 

'Spontaneous reversal of a Transfiguration is unusual but not unheard of,' she continued, 'and as this was the work of an only partly-trained wizard --' 

'Witch,' corrected Snape tersely. 

Professor McGonagall's beady eyes grew beadier yet, but she nonetheless amended, '-- wizard or witch. As for the failure of the reversal spell ... Transfiguration never was your best subject, Severus. You probably weren't bending your wrist properly on the down-stroke. Here, let me show you -- Potter, you may go.' 

'I know perfectly well how to reverse a Transfiguration!' Snape spat, as Harry exited the room. 

Harry had to fight down a grin. 

After leaving the hospital wing, Harry made his way to the library and sat down at the table where Ron and Hermione were studying. 'Guess what?' he said quietly, 'I saw Professor McGonagall. She was in the hospital wing, Snape took me there --' 

'Was she OK?' said Hermione. 'Was she -- human?' 

'As far as I could tell,' said Harry. 

He filled them in on what had happened. 

'_Another_ incident?' said Hermione, her eyes widening. 'Could Professor McGonagall have not been able to change back either? Perhaps there's something interfering with Transfiguration reversals ... Snape _was_ doing the spell correctly, I would've told him if he wasn't.' 

'Good thing you didn't, he'd've probably taken _fifty_ points off Gryffindor,' Ron snorted. 

Harry looked around carefully and said even more quietly, 'I don't know what was up with Professor McGonagall, but the only reason Snape couldn't change me back was because I wouldn't let him. Stupid thing to do, really, but I was angry with him for scaring me about Hedwig. When he was going to send for Dumbledore, I changed myself back.' 

'Harry, that's impossible,' said Hermione. 'There's no way for a Transfigured person to counteract a reversal spell -- or to reverse the Transfiguration themselves.' 

'I did,' said Harry. He tried to recall exactly how he'd done it. 'I could feel something pulling at me ... and I pulled back ...' 

The library and its contents swelled to enormous proportions, smells became much more pronounced and the odd feeling of being wrapped in a blanket returned. Ron leapt up, knocking over his chair, and Hermione let out a strangled scream. Harry, realising what he'd done, quickly transformed back. Some of the students at nearby tables were twisting their heads to stare, and Madam Pince the librarian was bearing down on them with a fire in her eyes, but luckily no one seemed to have noticed that Harry had been a snake for a few seconds. 

'Let's get out of here,' hissed Hermione. 

She and Ron hastily stuffed their books into their bags. The three of them hurried out the library just ahead of the wrathful Madam Pince. Hermione pushed Harry and Ron into the first empty classroom they came to. 

'You're an Animagus,' Ron said to Harry in amazement, as he shut the door. 

'But you couldn't be,' said Hermione. 'You didn't understand the Waldemar Effect until I explained it to you last week ... or the Petrovich Principle ... and -- and when did you have the time to train? Did _you_ get a Time Turner too?' 

'Of course not,' said Harry. 'I've never trained for anything except Quidditch, and I still don't understand that Petro-whatsit thingy. I just ...' 

He transformed himself again. Ron and Hermione, now hugely tall (and rather smelly), bent over to peer at him. 

'Harry?' said Ron. 

'Yeah?' Harry answered. 

Ron and Hermione jumped back. 

'You can talk!' said Ron. 

'Yeah ...' said Harry. 'And Animagi can't, can they? Not when they're animals?' 

'Usually not,' said Hermione. 'There was a raven Animagus in the eighteenth century who had her tongue split ...' 

Hermione pulled her Transfiguration book out of her bag and began leafing through it. Ron simply stood there, goggling down at Harry. 

Harry lay on the floor, exploring the very strange sensation of being a snake. He could feel vibrations in the flagged stones as people walked past the classroom. He tried slithering along the ground, which wasn't as easy as it looked. It was a most bizarre feeling to have his body curving back and forth from side to side behind him. 

He flicked out his tongue and the scent of Ron and Hermione filled his nose. The soapy parts of their respective odours were much the same, but their sweat smelled quite different, in ways Harry didn't really have the words to describe. Maybe he should find a real snake and ask it for advice ... 

'Hermione, could this have something to do with me being a Parselmouth?' said Harry. 'Can they turn into snakes as well as talk to them?' 

'Not that I've ever heard,' said Ron. 

'But Parselmouths are so rare ... there isn't all that much known about them,' said Hermione, raising her head from her book. 

'Dumbledore said I was a Parselmouth because Voldemort put some of his powers into me,' said Harry. 'Could he have been an Animagus and passed that on too?' 

'If he was, nobody knew about it,' said Hermione. 'Of course, that doesn't mean much where You-Know-Who's concerned. But even if you _are_ an Animagus, you shouldn't have been able to block a reversal spell.' 

'Harry, change back. This is weird ...' said Ron. He had been looking extremely nervous ever since Harry mentioned Voldemort's name. 

Harry changed back. 

'Could Malfoy have done this somehow?' said Ron. 'Accidentally Transfigured Harry into a snake Animagus instead of a snake?' 

'You can't make someone an Animagus by Transfiguring them,' said Hermione. 'Mind, it looked like Malfoy was trying to change Harry into a toad, not a snake,' she went on, sounding a bit puzzled. 'I don't think he was doing it quite the right way, but he shouldn't have got a perfect snake from a botched toad Transfiguration. Harry should've just gone all green and warty or something. We need to tell Professor McGonagall about this.' 

'Hermione, we can't!' said Harry. 'Snape would know I'd been messing him about! He'd say we faked the whole thing to get Malfoy in trouble! And it's illegal for me to be an Animagus anyway, I'm not registered with the Ministry!' 

'But if other Transfigurations haven't been working properly, Professor McGonagall needs to know!' said Hermione. 

'We don't know that this has anything to do with what happened to Professor McGonagall,' Harry said. 

'And Snape's taken enough points off Gryffindor for one day,' Ron put in. 'Let's at least wait and see if any other weird Transfiguration stuff happens first.' 

After a little more argument, Hermione reluctantly agreed to this. 

* 

Professor McGonagall was back at breakfast the next day, apparently none the worse for wear. Hermione, with Harry and Ron trailing after, went over to the staff table to ask her how she was feeling. 

'Quite well, thank you, Miss Granger,' said Professor McGonagall crisply, in a voice that discouraged further questioning. 

Ron and Harry had to drag Hermione back to the Gryffindor table -- she was plainly bursting to tell Professor McGonagall the whole story. Next Transfiguration lesson, Harry was very glad she hadn't. Professor McGonagall gave the class an extremely stern lecture on the dangers involved in the Transfiguration of human beings. 

'Any unauthorised experiments and I will personally make sure that all students involved are expelled,' she finished, her nostrils flaring. 

'You see?' said Harry to Hermione, once they were back in the Gryffindor common room. 'We can't tell Professor McGonagall, we'd be thrown out of school.' 

'But -- we don't know _why_ you can turn into a snake,' said Hermione. 'You're not a normal Animagus -- and human Transfigurations aren't safe, you heard Professor McGonagall. She might be able to --' 

'I'm not risking being sent back to the Dursleys over this,' said Harry flatly. 'If you go to Professor McGonagall, I won't back you up. I'll tell her you're lying, or having hallucinations ...' 

Hermione looked at him as though he had slapped her in the face. Harry felt terrible, but didn't back down. 

'It's for your own good,' he said. 'Professor McGonagall would know I couldn't have become an Animagus by myself, my marks in Transfiguration aren't good enough. And after Malfoy said you were the one who Transfigured me in Potions -- really, it's more likely they'd expel you than me.' 

'And I reckon that's why Snape did it,' said Ron suddenly. 

'_Snape?_' said Harry and Hermione, almost at the same time. Completely distracted from their quarrel, the pair of them rounded on Ron. 

'How could Snape have done it?' said Hermione. 'He wasn't even in the room.' 

'And he's rubbish at Transfiguration, Professor McGonagall said so,' Harry pointed out. 

'He must've given you a potion -- at breakfast that morning, probably,' said Ron. 'Like the Polyjuice Potion, but instead of turning you into another person, it made you able to turn into a snake. It activated when Malfoy tried to Transfigure you -- I bet Snape put him up to it and came in late on purpose. And Professor McGonagall -- funny how Snape knew exactly where to find her after you told him she was missing. No doubt he's planning to blame us for that one too. We'd be playing right into his hands if we said anything about this.' 

Hermione looked sceptical. 'There're potions that can turn people into animals, but I've never heard of one that would let someone change back and forth.' 

'Well, I think Snape knows a few things about potions you don't,' said Ron. 'He _is_ -- ' 

Ron abruptly fell silent, staring at Hermione in astonishment. Harry didn't blame him -- never before had he seen such utter horror in Hermione's face. 

'No,' she breathed. 'He _wouldn't_ have ...' 

'Wouldn't have _what_?' demanded Ron. 

'There _is_ a potion ...' Hermione whispered, staring at the floor. 'It lets werewolves transform at will, painlessly, and keep their minds ... but to make it you have to -- to kill someone.' She looked up at them bleakly. 'You-Know-Who invented it. That was how he got a lot of the werewolves on his side. And how the Wolfsbane Potion was discovered -- it was the closest anyone could get to a formula that used legal ingredients.' 

'But I'm not a werewolf,' said Harry uneasily. 

'You're a Parselmouth,' said Hermione. 'You must have a bit of snake in you somewhere, to be able to talk to them.' 

'_Kill_ someone?' said Ron. 'You mean Snape gave Harry a potion with bits of _people_ in it? Eurgh!' 

'And not bits they could spare, either,' confirmed Hermione. 

Harry felt as ill as Ron looked. 

'But if it was a potion, it should've worn off by now,' said Hermione more briskly. 'Harry, can you still change into a snake?' 

Harry concentrated for a moment. 'I feel as though I could,' he said, with some relief. 'But I'm not going to. Professor McGonagall said it was dangerous, and what if someone saw?' 

'Snape might still be putting the potion in your food,' said Ron, clearly unwilling to give up on his idea. 

'If he is, he's putting it in your food too,' said Harry, annoyed. 'We eat out of the same dishes. Everyone in Gryffindor would be getting some!' 

None of them had much appetite that evening at dinner. Harry picked at his food morosely, wondering if he'd ever dare eat anything from the Hogwarts kitchens again. He'd been expecting Snape to try and get some sort of revenge on him, but this was worse than anything he could have imagined. Snape would have to be truly mad, killing someone just to make a potion to get Harry into trouble. If he was willing to commit murder, why not simply kill Harry? 

Harry was worried enough that he skipped breakfast the following morning. During lunchtime, he slipped down the tunnel behind the one-eyed witch into Hogsmeade, where he bought a large bag of sandwiches from the Three Broomsticks and a box of Chocolate Frogs from Honeydukes. Next three days, Harry stayed away from Hogwarts meals entirely, but after finishing off the last of his food from Hogsmeade, he was still able to transform. 

* 

In the weeks that followed, there were no more Transfiguration accidents, nor did Professor McGonagall miss any more classes. Hermione spent a great deal of time in the library, but found no useful information. After the sandwich experiment, Harry didn't try to change himself into a snake again. Apart from not wanting to be expelled, he'd been made rather nervous by Professor McGonagall's lecture on human Transfigurations gone awry. 

Snape made no move to unmask Harry as an illegal Animagus. Malfoy on several occasions threatened to turn Harry into a snake again and leave him that way. He seemed immensely frustrated at how thoroughly unimpressed by this Harry was. If Malfoy had somehow given Harry the power to become a serpent, he didn't appear to realise it. 

Most unfortunately for Malfoy, about the fourth time he did this Professor Moody overheard him. Moody hauled Malfoy off to his office, muttering something about 'a _long_ sharp shock, this time'. Malfoy reappeared at dinner that evening, looking considerably paler than usual and severely shaken. The threats stopped, and for the next few days he avoided Harry altogether. 

Then, at the end of October, Harry was chosen as the fourth Triwizard Champion, and the snake incident was driven from everyone's mind. 

* 

So matters stood, until one afternoon soon after the Christmas holidays. Harry had forgotten his Charms book in Gryffindor Tower and was going back to get it when Snape's voice stopped him in his tracks. 

'Potter!' 

Harry turned and felt a sudden nasty pang of apprehension. Snape was obviously trying quite hard not to smile. He only ever looked that pleased with himself when Harry was in very deep trouble. 

'So you finally found the counter to the Tangler Charm,' said Snape, a malevolent gleam in his eyes. 

Harry's nervousness was replaced by utter confusion. Not only had he _not_ found the counter to the Tangler Charm, he hadn't even known such a spell existed. 

'The what?' he said. 

'I know you've got it,' said Snape, his eyes glittering. 'You were clever, but not clever enough. You broke the Tracing Charm on the card. You broke the Tracing Charm on the Spellotape. You neglected, however, to break the Tracing Charm on the chalk dust on the back of the Spellotape!' 

Light suddenly dawned. 'Someone took your Chocolate Frogs card?' 

'Yes!' snarled Snape. 'You did! Pull out your pockets!' 

Harry pulled out his pockets, taking out some Chocolate Frogs, his wand and the latest Quidditch scores from the _Daily Prophet_. 

Snape glared at him. 'Your bag, empty it out!' 

Harry emptied out his bag. Books, quills, parchment and bottles of ink spilled onto the floor. Snape waved his wand, causing each of Harry's books to magically rise into the air, flip over and shake itself out. He turned Harry's bag inside out and ran his hands over every inch of it, searching for secret compartments. He tapped each pack of Chocolate Frogs, making the wrappings go transparent to reveal the cards they carried -- Nostradamus, Anne Boleyn and Saint-Germaine, but no Harry Potter. 

'So you've already made it to Gryffindor Tower and back,' said Snape, sounding furious but undeterred. 'Fast work, but I'm sure you know all the shortcuts. Very well. We'll go back there and have a search of your dormitory. Follow me.' 

Harry followed. He wasn't particularly worried about his dormitory being searched. Snape wouldn't find his Famous Wizard card there ... but he _would_ find the two copies of it Harry had dug up over the summer. Harry felt twinge of fear, but only for an instant. The other cards and the letter they all came in should be proof enough that neither was Snape's missing card. 

Harry wondered idly what Snape would make of the card with Sirius as a dog on it. Although Snape knew Sirius was an Animagus from overhearing Professor Lupin in the Shrieking Shack, he didn't know what animal Sirius transformed into, only that it was very large ... _and that its nickname was Padfoot_. 

Utter panic flooded through Harry. He couldn't let Snape find the letter and cards -- not only would Snape realise what kind of animal Sirius was, he'd have a picture of him to give to the Magical Law Enforcement Patrol. And Sirius was back in England now ... Harry had to get to Gryffindor Tower before Snape and get rid of the evidence. With a sickening sense of deja vu, Harry darted past Snape, ignoring his enraged shout, and tore off down the corridor. 

* * *

_ Disclaimer: All characters and concepts from the Harry Potter series copyright J K Rowling. _


	3. The Serpent of Madam Turpin

  
  


— CHAPTER THREE — 

_The Serpent of Madam Turpin_

  
Harry ducked round the corner, yanked back a tapestry and went racing down the passageway behind it -- luckily he _did_ know all the shortcuts to Gryffindor Tower, thanks to the Marauder's Map. Snape would no doubt realise where Harry was going ... but would he know the password to get in? If he did, Harry wouldn't have much time to act ... and the cards and letter were charmed against damage; Harry couldn't just toss them into the fireplace. 

He'd have to use his Invisibility Cloak to sneak past Snape ... hide the cards inside the one-eyed witch's hump or behind the mirror on the fourth floor. Snape was going to hang him out to dry for this one ... maybe Harry could explain to Dumbledore afterwards, privately ... 

Harry burst from the passageway, clutching a stitch in his side. He sprinted to the end of the Gryffindor corridor, gasped out the password to the Fat Lady, scrambled through the portrait hole and dashed across the common room, up the spiral staircase and into the fourth-year boys' dormitory. 

To his astonishment, someone was already there, rifling through his things -- but it wasn't Snape, it was a witch. She gave a small shriek and spun around. With a bit of thought Harry identified her as Madam Turpin. Plump, nondescript and middle-aged, she'd been hired on as staff early in the year ... something to do with the kitchens. Dumbledore had introduced her one night at dinner ... 

'What're you doing?' Harry demanded. 

'You scared me half to death,' she said reproachfully, one hand pressed to her chest. Then in a flash she pulled out her wand and sent ropes shooting out of it, which lashed themselves around Harry's arms and legs. Before he could open his mouth to protest, she said briskly, 'That Famous Wizard card -- the one of you as a baby -- where have you hidden it?' 

'I _haven't_,' said Harry in exasperation. 'I don't know what happened to Professor Snape's card, but I swear, I didn't take it!' 

'Of course not, dear,' said Madam Turpin. '_I_ took it. I meant your one. I know you have it, you and your friends were talking about it one evening at dinner last fall.' 

Harry remembered. Draco Malfoy had been in particularly fine form that day in Potions -- ickle Harrykins this, ickle Harrykins that. Harry, Ron and Hermione had been wondering how much longer Snape was planning to leave the card up on the blackboard, and puzzling over how he could have got hold of it in the first place. Come to think of it, Harry did recall that Madam Turpin had been bustling around in the background ... 

He stared at her blankly. 'You took Snape's card -- and you want mine -- but why?' 

'For the gold, of course,' said Madam Turpin. 'I'm a thief, dear, this is how I earn my living ... and you _will_ tell me where you've hidden that card, unless you want to spend the rest of your life as a snake ...' 

'You --?' said Harry, now truly dumbfounded. 

'Yes, me. I may not look it, but I know a lot about Transfiguration. I'm a thief -- ' Madam Turpin vanished for a second and a small brown ferret took her place, '-- and an Animagus,' she said, reappearing. 'I can enchant Transfigurations so they can't be reversed -- Snape was only able to bring you back after I removed the spell, and not even Albus Dumbledore could figure out what I did to Professor McGonagall.' 

'So ...' said Harry carefully, '... it was you who changed me back, when Snape couldn't?' 

'Yes, dear. I hope you weren't too badly frightened. Professor Snape needed something to occupy his thoughts. He almost caught me in Professor McGonagall's rooms, and she almost caught me in his classroom, right after I'd escaped the Tangler Charm. She'd been prowling around as a cat that night. I'd hoped to convince her that her Animagus transformation had become unreliable. A transformed cat might too easily recognise a transformed ferret ...' A look of extreme annoyance came over Madam Turpin's face. 'I hadn't expected anyone to come looking for her so quickly. Really, Professor Snape is the nosiest man in the world ... but to go into a woman's bedroom like that ...' 

'I knocked first,' said a voice from the dormitory door. 

Harry whirled, over-balanced and fell backwards onto the floor, nearly hitting his head against the post of Ron's bed. Madam Turpin shrieked again, but before she could raise her wand Snape had disarmed her and cast the full Body-Bind. 

'That time,' he added, with a nasty smirk. 

Harry sat up as best he could, bound from neck to ankles. Snape glared down at him. 

'I ought to bring you to the Headmaster's office like that,' he said softly, 'and if you ever run from me again, I will. We shall be taking Madam Turpin to see Dumbledore. He should be quite relieved that the cause of last term's Transfiguration mishaps has been discovered.' Snape pointed his wand at Harry, paused and gave him a twisted smile. 'Unless you have some reason to believe Madam Turpin is not the guilty party after all ... Perhaps she has been framed by Miss Granger's cat ... or maybe Mr Longbottom's toad is the true culprit ...' 

'No, sir,' said Harry quietly. 

In fact he was fairly certain that Madam Turpin _wasn't_ the person behind the snake incident: she didn't seem to realise it had been Harry himself who blocked Snape's reversal spell and then transformed back on his own. Harry didn't think it wise to mention this to Snape, however. 

The ropes vanished and Harry got up. Most fortunately, Snape did not insist on completing Madam Turpin's search of Harry's trunk before setting off. He made Harry walk ahead of him ('where I can keep an eye on you') with the Body-Bound Madam Turpin floating between them. They must have made an extremely peculiar sight as they went down the corridors, past the gargoyle sentry and up the revolving stairs to Dumbledore's office. 

Harry knocked and the door swung open. Dumbledore looked up from his desk. 

'Harry, Severus,' he said pleasantly. Then, in a more puzzled tone, 'Jane?' 

'Madam Turpin has just claimed responsibility for tampering with Professor McGonagall's Animagus transformation and thwarting my reversal spells,' Snape said. 'I overheard her telling Potter -- she had him tied up and was searching his trunk.' 

Harry nodded in confirmation. 'She was after Snape's Famous Wizard card, and she'd found out I had another copy.' 

Snape looked down at Harry, his lip curling. 'Because she's president of the Harry Potter fan club, I suppose,' he sneered. 'Just because Madam Turpin has confessed to one crime, don't think you can --' 

'Because it's _valuable_,' said Harry. 'Worth hundreds of Galleons.' At Snape's disbelieving look, he added, 'Ron said so, he has a value guide.' 

Dumbledore raised his wand to perform the counter-curse on Madam Turpin. 

'Watch out, she's an Animagus -- a ferret,' Harry said quickly. 

Dumbledore set his wand back down. 'I think Minerva should hear about this,' he said in a very serious voice. 

Dumbledore tossed a handful of glittering powder into his fire and soon Professor McGonagall was clambering out of the fireplace. Snape told his part of the story -- he'd arrived in the dormitory just as Harry was asking Madam Turpin if she'd reversed the snake Transfiguration -- and Harry told his. He claimed he'd run to Gryffindor Tower after hearing Snape's card had been stolen as he was afraid the real criminal might try to take his one too. 

Professor McGonagall was frowning thoughtfully as Dumbledore shut and magically locked the door before releasing Madam Turpin. 

'What do you have to say to this, Jane?' said Dumbledore mildly. 

Madam Turpin gave a frightened squeak and scuttled behind Dumbledore's desk. '_He_ did it!' she said in a petrified voice, pointing at Snape. 'I caught him in the kitchens, trying to put a potion into Professor McGonagall's water jug! He made it all up to blame me -- told the boy he'd turn him back into a snake and pickle him if he didn't go along ...' 

The murderous look on Snape's face would have convinced anybody who didn't know better that Madam Turpin was telling the truth. Cornelius Fudge would have had him arrested on the spot. Even Harry, who knew quite well that Snape hadn't threatened him with pickling, had to wonder -- Madam Turpin's accusation was so close to what Ron suspected Snape of doing to Harry. 

Snape had just taken a step towards Madam Turpin when Professor McGonagall held up her hand. 'Leave her to me, Severus!' she barked. 

Harry stared at her, amazed. Never before had he heard Professor McGonagall's voice so filled with fury, or seen her mouth go so thin. With a wave of her wand, every object in the room -- including Harry, Snape and Dumbledore -- rose off the floor and hovered three feet in the air. She pointed the wand at Madam Turpin, who turned back into a ferret, then transformed herself into a cat. 

Round and round the room the angry, hissing cat chased the squealing, terrified ferret. After a minute or so of this, the ferret stopped short right under Harry and gathered itself up for a jump. Harry tried to back away -- he didn't want it climbing up his leg -- but floating above the floor as he was, his feet merely churned the air. 

Luckily at that moment the cat pounced. It seized the ferret by the scruff of its neck and shook it back and forth like a terrier worrying a rat. When the cat finally let the ferret drop, Professor McGonagall and Madam Turpin reappeared. Professor McGonagall's teeth were bared and several strands of hair had flown loose from her bun. Madam Turpin cowered away from her, shaking with fright. 

'Now, _Enid Kelly_ ...' Professor McGonagall snarled. 'Are you ready to tell us the truth?' Madam Turpin gazed at her in terror, took a couple of gasping breaths and fainted dead away. 

* 

'How did Professor McGonagall know her real name?' said Hermione. 'Enid Kelly wasn't on the Ministry's registry when I checked it last year ...' 

'She was,' said Harry. 'The Australian Ministry's registry, that is. Not that it's done them much good. Madam Turpin -- I mean, Kelly -- hasn't got any unusual markings and so many thieves use enchanted ferrets ... She's been a suspect in loads of cases in Australia, but nobody could ever prove it was her and not some other ferret. It's good Professor McGonagall keeps up with that sort of thing -- once she called Madam Turpin by her real name, she knew the game was up.' 

'What'd she done to Professor McGonagall?' said Ron. 

'Slipped her a Confusing Concoction,' said Harry. 'Animagi -- if they transform while they're Confused, as animals it can take days for their minds to come back, unless someone reverses the Transfiguration. It happened to Madam Turpin once, that's how she knew about it. Snape thought it was something like that, but he reckoned Fred and George did it as a prank. That's why he was so hacked off at them that day.' 

'But how on earth did she make you able to change into a snake?' said Hermione. 

'She -- she swears she didn't,' said Harry. 'I asked about that potion you told me about and Snape didn't think she could've given it to me. She didn't seem to know I _could_ turn into a snake. Course, as many times as she'd changed her story ...' 

At first Madam Turpin hadn't even been willing to admit being the cause of Professor McGonagall's difficulties. 'Yes, I tried to steal the cards,' she said tearfully. 'But I didn't interfere with any Transfigurations -- how could I have? I was only trying to scare the little dear ...' 

No one had an answer to this, until Harry rather hesitantly spoke up. 'Hermione, she thought Sn-- somebody -- gave me that potion Voldemort made for werewolves -- put it into the food at breakfast. Because I'm a Parselmouth ... and Malfoy was trying to turn me into a toad not a snake.' 

Dumbledore's eyes flashed. Professor McGonagall's fists clenched; she looked on the verge of attacking Madam Turpin as a woman. Snape gave a contemptuous snort. 

'Exactly the sort of melodramatic nonsense Potter and his friends would come up with,' he said. 'The Lycaon Potion is too delicately balanced to be taken with most foods, and in any case, you'd have certainly noticed the taste.' 

He turned to Madam Turpin, a most unpleasant smile stretched across his thin face. 

'Which isn't to say they won't be believed. Our current Minister for Magic is not a wizard known for his logic. If he thought you'd given a potion made from human remains to the sainted Harry Potter ... really, life in Azkaban would be the best you could hope for. Perhaps, being a foreigner, you are not aware that the use of the Dementor's Kiss has recently been revived in this country?' 

Madam Turpin looked about to really faint -- Harry was fairly certain she'd been faking it the first time. 

Snape pressed his advantage. 'As we'd already suspected the use of a potion in McGonagall's case -- one of the few things she remembers from that morning is taking a drink of water --' 

At that Madam Turpin had finally cracked and confessed to giving Professor McGonagall the Confusing Concoction. She still denied having done anything to Harry, however. 

'Dumbledore says she'll probably get a fortnight in Azkaban for using a dangerous potion on someone,' Harry told Ron and Hermione. 'Unless the Australian Ministry lodges a protest -- and likely they won't, they've been trying to get her for something for ages. Then she'll be deported.' Harry brightened somewhat. 'And Dumbledore's making Snape take that card down! He said if it was so valuable people were breaking into Hogwarts to steal it, it needed to be kept somewhere safer.' 

'How valuable _are_ those cards, anyway?' said Hermione. 

Harry looked at Ron questioningly. 

'The last one I heard of went for around seventeen hundred Galleons,' Ron said. 'Mind, that was several years ago. None of them have been up for auction since then, which is bound to drive up the price ...' 

'Still, coming all the way from Australia ... to try and steal something from Hogwarts ... and after she nearly got caught once ...' said Hermione. 'It hardly seems worth it. Wouldn't it have been easier to rob one of those other collectors?' 

'Other collectors would know what that card was worth. They'd keep their ones protected, not hanging out in plain sight,' said Ron. 

'Snape _was_ protecting his,' said Hermione. 'Tangler Charms are very hard to cast -- he probably had to get Professor Flitwick to do it for him -- and even harder to get around. Snape was _expecting_ someone to try and steal it --' 

'Snape was expecting _me_ to try and steal it,' interrupted Harry. 'He had no idea it was valuable, he'd got it because he was in on the investigation of Theobrom and Raniday. That letter from Sabella Theobrom he read was sent with one of the cards with my parents, not Sirius Black. Dumbledore asked Snape about it because Snape had shown him _that_ card. It was Dumbledore who complained to the Ministry ...' 

'Why was Sabella Theobrom sending Snape _any_ Famous Wizard card of you?' said Ron. 'Not a collector, is he?' 

'Dumbledore says she and Snape were in the same year in Slytherin,' said Harry. 

'That's still a bit strange,' frowned Hermione. 'If they were in Slytherin together, she must've known Snape hated your father. Why send Snape a Famous Wizard card with his picture on it -- and that soppy letter about what a sweet baby you were? And even if Snape was behind the complaint, why would he be helping with the Ministry investigation? He's never worked for Magical Law Enforcement, has he?' 

'If he has, Dad's never said anything about it,' said Ron. 

Harry went on more quietly, 'I told Dumbledore about the letter and cards I found, after everyone else had left. He said he'd take them to Gringotts for me. Yours too, Ron. Sorry, but until we find some way to prove Sirius is innocent -- if anyone saw that dog ...' 

Ron shrugged. 'Ah, well -- Mum would've made me give it back to you anyway when she found out what it was worth.' 

'It's still yours!' said Harry fiercely. 'As soon as Sirius is cleared you'll have it back ... and you, d'you want the other one, Hermione? I know you don't collect them --' 

'I think Sirius might want to have it,' said Hermione diplomatically. 'What I want is to know why you can change into a snake.' 

'As long as it's not Snape giving me that potion, I don't care,' said Harry. 'Which I reckon he wasn't -- Dumbledore said he was telling the truth about it tasting bad, and now we know why he was acting so weird last fall.' 

Hermione was clearly not at all mollified by this. 

'Just forget it, all right?' Harry told her. 'Professor Moody's going to have a talk with Madam Turpin before the Magical Law Enforcement Patrol takes her away. If she was up to any other funny business, he'll get it out of her ...' 

— THE END — 

The sequel to this story  
is called  
"The Butterflies" 

* * *

**Related Stories:**

Under the Rose Bush - Tells how Harry and Snape found their Famous Witches and Wizards cards. 

An Unwelcome Visitor - Explains why Harry was afraid Snape had gone mad and might harm Hedwig. 

The Butterflies - Continues (in a very roundabout way) the story of the serpent and the Chocolate Frogs card. 

The Serpent of Lord Voldemort - Harry's snake transformation comes in unexpectedly useful. 

Thank you to all the people who've reviewed my stories. 

* * *

**Questions from Reader Reviews:**

_ This question was actually asked in a review for "The Serpent of Lord Voldemort", but as it pertains to this story (and won't be answered in any future stories), I'm answering it here. _

How do Tangler Charms work? 

A Tangler Charm will catch and hold in place anyone who touches the object on which the charm was cast. Removing a Tangler Charm is very difficult, as they can be performed using an infinite number of different combinations of wand movements, and the countercharm will only work if it's done with exactly the same combination of wand movements as the Tangler Charm it's trying to break. 

Casting a Tangler Charm isn't easy either, as not just any combination of wand movements can be used -- they all have to balance each other out by the end of the charm. It's a bit like drawing one of those Celtic knotwork patterns in the air with a wand. The more complicated the wand movements, the harder this is to do, but simple combinations can be too readily broken by pure guesswork. 

When Madam Turpin was caught by the Tangler Charm the first night, she was able to wriggle free by turning into a ferret. To actually steal the card, however, she needed to figure out the countercharm. Being an experienced magical criminal, Madam Turpin was able to determine the correct pattern of wand movements by feeling the resistance of the spell to unsuccessful countercharms. This involved a lot of trial and error, however. The spell Snape had put on the card was _very_ complex (Hermione was dead wrong about him needing Flitwick's help; he has the exactly the right sort of twisted mind for Tangler Charms), and of course Madam Turpin had to be careful not to get caught while she was doing it. 

* * *

_ Disclaimer: All characters and concepts from the Harry Potter series copyright J K Rowling. _


End file.
